1. Field of the Invention
The present invention relates to a medical stent and a production method of a medical stent. This application is a continuation application based on PCT Patent Application No. PCT/JP2011/074931, filed on Oct. 28, 2011, claiming priority based on Japanese Patent Application No. 2010-244230, filed on Oct. 29, 2010, the contents of both the Japanese Patent Application and the PCT Application are incorporated herein by reference.
2. Background Art
Conventionally, in order to dilate a narrowed area formed at a lumen in living body, such as a blood vessel, a digestive tract, or a bile duct and maintain the opened state, a medical stent (hereinafter also referred to as a “stent”) has been indwelled at the narrowed area.
Among them, for example, a stent which is used for a bile duct, as shown in Japanese Unexamined Patent Application Publication No. 2006-87712, is formed in an approximately tubular shape. Flaps (elastic members) which are opened in a natural state and deformed so as to be closed by a given external force are respectively provided at the distal end side and the proximal end side of the stent. The flaps are formed by cutting and raising a member made of resin, which is used in the outer circumferential surface of a main body of the stent.
These flaps are locked to an inlet port of a duodenal papilla and an outlet port of a narrowed area of a bile duct, thereby fixing the stent to the narrowed area. Subsequently, the stent is collected with use of a portion locked to the inlet port of the duodenal papilla in the stent.
A stent having another configuration shown in Japanese Unexamined Patent Application Publication No. 2005-278993 is not provided with a flap and is constituted by connecting a plurality of materials to each other. This stent is provided with a stent main body formed in an approximately cylindrical shape and having a plurality of openings formed therein, a coating resin layer disposed in an inner cavity of the stent main body and formed of a porous resin film, and a tubular cover which connects the stent main body and the coating resin layer to each other.
The tubular cover is formed of thermosetting resin or the like having no adhesiveness with porous resin. The stent main body is subjected to primer treatment in order to enhance adhesiveness with the thermosetting resin. The tubular cover is connected to the coating resin layer by flowing a solution of thermosetting resin dissolved in an organic solvent into pores formed in the porous resin film and then solidifying it.
Further, a stent transplantation piece described in Japanese Unexamined Patent Application Publication No. H10-305050 is also not provided with a flap, and a lattice member formed in a tubular shape and a sleeve disposed so as to cover the outer circumferential surface of the lattice member are connected to each other by a silicone adhesive.